Automatic turret lathe



Aug. 19, 1924.- 1,505,131

' T. E. BUSCHMANN AUTOMATI C TURRET LATHE Filed March 11, 1921 2Sheets-Shet 1 Aug 19 1924, I 1,505,131

' T. E. BUSCHMANN AUTOMATIC TURRET LATHE Filed March 11, 1921 2Sheets-Sheet 2 Patented Aug. 19, 1924.

UNITED STATES THEODOR EUGEN BUSCI-IMANN, OF GHEMNITZ-KAPPEL, GERMANY.

AUTOMATIC TURRE'I LATHE.

Application filed March 11, 1921.

T all whom it may concern Be it known that I, Tnnonon EUGEN BUSCI-IMANN,a citizen of the German Republic, residing at Chemnitz-Kappel, Germany,have invented certain new and useful Improvements in Automatic TurretLathes (for which I have filed applications in Germany Nov. 3, 1919, andOct. 9, 1916), of which the following is a specification.

My invention relates to a screw-cutting device for automatic toolturrets, and more particularly has for its object to provide thepossibility of employing in connection with automatic turret lathesfitted with a tool turret for the purpose of changing tools, a

screw-cutting device in the case of which the die spindle is adapted toproduce the thread by being operated at a suitably increased number ofrevolutions relativelyv to the spindle.

In order to enable the rotary motions of the tool turret to be carriedout Without impediment, the driving motion is furnished by a shaftarranged in the centre of rotation of the revolving tool box, as hasbeen done with automatic tool turrets. In accordance with my invention,the said driving shaft is adapted to support the coupling elementsserving to drive the die spindle, so that this latter with its accessoryparts may be conveniently housed within the space available.Furthermore, the connection between the driving shaft and the diespindle is established on such lines that the latter will beautomatically engaged in the course of the movemen executed by the toolturret which causes the die to be brought up to the work piece, and thatit will be as suddenly disengaged, after the thread has been completed,as a result of its displacement by the die. To this end, there isarranged on the die spindle a cam which, when the thread has been cut,will, by reversing a lever, release a disengaging pin which will thenjump for ward into the coupling, pull this latter apart and keep it inthis position until the die has completely run oft from the thread.

In the drawings affixed to this specification and forming part thereof,two tool turrets (of the Browne and Sharpe type in Figs. 1 to 5 and ofthe Cleveland type in Figs. 6 to 8) and embodying my invention areillustrated by way of example. In the drawings Fig. 1 is a section, ofthe tool turret pro- Serial No. 451,649.

vided with the improved screw-cutting device.

Fig. 2 is an end view thereof,

Fig. 3 is a detail view illustrating the manner of disengaging the diespindle,

Figs. 4 and 5 are detail views disclosing the disengaging lever in theposition when thrown in and when thrown out, respectively.

Fig. 6 is a cross section of a tool turret of a Cleveland lathe.

Fig. 7 is a side elevation of Fig. 6, and

Fig. 8 is a detail view on an enlarged scale.

Referring to Figs. 1 to 5 of the drawings, the tool turret 1 is rotatedwhen changing tools by means of an indexing gear wheel 2 mounted on thehollow shaft 3 of the tool turret. I shall not here enter into a moredetailed description of the feed mechanism and the further constructionof the tool turret mechanism, since it is assumed that these elementsare generally known to all familiar with the art. Attention is onlydirected to the fact that in the type of construction here shown, thetool turret is mounted on a carriage affording the possibility of movingthe tools up to the workpiece. The screwcu'tting device is inserted in ahole lformed in the tool turret which serves to accommodate the tools.At the free end of the shaft of the tool turret there is loosely mounteda belt pulley 5, which is kept running continuously and serves as adriving means for the die spindle l5. Rigidly connected to the saidpulley is a clutch ring 6. Within the interior of the shaft of the toolturret there is lodged a driving shaft 7 carrying at its free end aclutch member 8. At the opposite end of this shaft there is mounted abevel wheel 9 and a disengaging cam-faced clutch member 10. The drivingshaft 7 is shiftable endwise and is acted upon by a spring 11 in such amanner as to cause the coupling members 6, 8 to constantly strive toenter into engagement. lVithin the hole formed in the tool turret thereis inserted a bushing 12, the bore of which is adapted to accommodate adriving sleeve 13 operated by a bevel. wheel 14:. The driving sleeve 13serves to transmit the rotatory motion to the die spindle 15 which isconstantly drawn by a spring 16 toward the interior of the tool turret.On the die spindle there is mounted the disengaging cam 17, whileparallel to this said shaft there are located the disengaging pin 18engageable with the clutch member 10 and a spring 19. On thisdisengaging pin there is arranged a sleeve 20 having two arms 21 and 22and provided at its hub with inclined faces adapted to cooperate withsimilar inclined faces 23 appertaining to a stationary sleeve 24:. Forthe purpose of bringing the screw cutting device into engagement, thereis provided a stationary pin 26 at the carriage of the tool turret.

In Fig. 1 the drive mechanism for the die is shown in the position itassumes immediately upon conclusion of the screw cutting operation. Inthis position, the tool turret is fed forward in the indexing operationfrom tool to tool. During the lastpart of the indexing movement of thesaid tool turret for the purpose of bringing the die into its operativeposition, the arm 21 of the lever moves past the stationary pin 26 (Fig.and in so doing is turned sideways. As a result, the inclined faces 23of the sleeve 20 move up the stationary sleeve 2st and draw thedisengaging pin outward counter to the action of spring 19, so that nowthe throw out clutch 10 will be released. Spring 11 at the same timedisplaces the driving shaft 7 and thus brings coupling elements 6 and 8into engagement, whereby the die. spindle axis will receive motion frombevel wheels 9 and 1a. Fig. 3 illustrates the disengaging pin in itsoperative position. The die is moved up to the workpiece by the toolturret for the purpose of initiating the cutting operation. Inaccordance with the die proceeding with the cutting operation, the diespindle gradually comes to be displaced endwise until the cam 17,mounted on said spindle, reaches arm 22 of lever and reverses thislatter, sothat now the inclined faces 23 will slide down into sleeve 2a.Thus, the disengaging pin 18 is brought within reach of the externalcurved cam face arranged on the throw out clutch l0, displaces thedriving shaft 7, pushes the clutch elements 6 and 8 apart again andlocks them in thisposition, so that the die may now run off from thefinished thread.

It is obvious that the driving motion may also be transmitted by otherclutch means. I may also provide other means within the meaning of theclaims for causing the operation of the preferable cam-faced clutchmember at the termination of the indexing movement.

In the construction illustrated in Figs. (3 to 8, the workpiece 2G isdriven by the main drive head stock and is successively tooled by thedifferent tools. a part of which are honsed in the tool turret.

denotes the. casing surrounding the tool turholes I of the tool turret.

ret and within which this latter is adapted to turn when changing tools.The tool turret is mounted on a hollow shaft 28. lVithin the shaft 28there is located the driving shaft 30 provided at its rearward end (notshown) with a driving wheel serving to continuously keep shaft 30 inmotion. ()n this last-named shaft is fixed a clutch 31 cooperating witha displaccable clutch 32. Clutch 32 is provided with a transverse slot33 with which the pins 34 of sleeve 35 are adapted to enter intoengagen'lent and whereby this said sleeve is connected in such a mannerwith clutch 32 as to enable this latter to be displaced. ithin sleeve 35there is arranged a spring 36, which, when the clutch is released,causes both clutch elements to be thrown into engagen'ient. On theperiphery of the clutch element 32 there are formed inclined faces 37adapted to effect engagement and disengagement, while on the sleeve 35there is keyed a transmission wheel 38 secured in its position by a nut39. The sleeve 35 is housed in the bushing 40 arranged in the centre ofthe tool turret.

The screw-die is inserted in one of the The bushim 41 is spring-actinglvsecured in the tool hole 4. Within the said bushing there is located thedriving sleeve 42 on one end of which there is keyed the driving wheel42% being further secured in its position by a nut 44-. 45 is the diespindle the forward extremity of which is shaped to form a head for thereception of the screw-die 46. Spindle 4F is axially movable and securedto the sleeve 25 by a key 47. On the said spindle there is moreoverarranged a cam 18 serving to cll'ecl its disconnection from the drivingelements. On the rear end of the spindle there is disposed a spring 49,secured by an adjusting collar .30 and serving to retract the spindlewhenever re quired. This said spring bears up with its one end againstan intermediate collar 51 secured within the tool hole by a screw 52.The means employed to connect and (liSCOllnect the driving mechanismconsist of a simple bolt 53. This bolt is provided with teeth with whichthe teeth of the ratchet wheel 54 are adapted to gear and the shaft 55of which is mounted in the sleeve 56. ()n the said shaft 55 there isfixed a lever 57 serving to establish the connection with the drivingmechanism. Vith the ratchet wheel 54 there is coupled a disc 58 providedat its front end with two continuous V-shaped. slots 59 which a. bolt(30 possessing a conical or triangular projection 61 is :nlaptt-ul toengage. For the purpose of enabling the bolt til) to accommodate apressure spring (i2, the sai-il bolt is made hollow. By this means theratchet wheel 5+ may be locked in its end position. lfiv means of a key(323 the spring actuated bolt is secured against rotation.

At the bearing 27 of the tool turret there is provided a stationary pin64 serving to rock the lever 57 outward when establishing the connectionwith the driving mechanism.

The manner of operation of the device is as follows:

As the tool turret l executes the last partial indexing movement, inorder to bring the die into its operative position, the lever 57 movespast the stationary pin 64. Lever 57 was originally located in theposition indicated by dash lines, but is now shifted by pin 64 into theposition shown in full lines. At the same time, ratchet wheel 54withdraws bolt 53 for such a distance that clutch 32 will be releasedand brought into engagement by spring 36 wit-h the permanently rotatingclutch element 31; The die spindle 45 is driven by sleeve and thetransmission Wheels 38 and 43. The cutting operation on the part of thedie is initiated by the endwise displacement of the tool turret. Thecutting operation having set in, the die spindle is gradually shifted bythe cutting-tool until the cam 48 attains bolt and in so doing effectsits displacement. Bolt 53 is thus shifted toward the clutch member 32which in the course of the rotatory motion rolls with its inclined face37 on said bolt 53 and is by these means disengaged from the teeth ofthe permanently rotating clutch element 31, so that now the die spindle45 will be brought to a stop and the die itself will run clean off fromthe finished thread by the action of the spring 44. The V-shaped slots59 formed in the disc 58 arranged at the ratchet wheel 54 serve to lockthe coupling operating bolt or rack bar 53 in its extreme positions.

It may be noted in conclusion that the continuously rotating shaft mayalso be used for driving drilling devices such as are required fordrilling small holes. A device of this kind is likewise illustrated inthe drawings in dotted lines.

I claim z 1. The combination with an intermittently rotatable toolcarrier, of axially movable rotatable tools on said carrier, tooldriving means on the carrier, a cam-faced coupling member in operativeconnection with said driving means and said tool, spring-actuatedcoupling operating means on the carrier, means on said tools engageablewith said coupling operating means, and relatively stationary operatingtappets in the circular path of movement of the coup-ling operatingmeans.

2. The combination with an intermittently rotatable tool carrier, ofaxially movable spring actuated rotatable tools, a driving shaft in saidrevolving tool carrier, camfaced coupling means opei'albly connectingsaid driving shaft to said tool, coupling controlling means on saidcarrier and engageable with said coupling, relatively stationary meansoutside of said carrier in the circular path of movement of saidcontrolling means, and means on said tools engageable with saidcontrolling means and operating tappets on said carrier.

3. The combination with an intermittently rotatable carrier, of anaxially movable, rotatable spring-actuated screw cutting tool, a drivingshaft, located in said carrier, a cam-faced coupling member cooperatingwith said shaft and said tool, spring influenced controlling means onsaid carrier engageable with said coupling, means on said toolengageable with said controlling means, and operating tappets outside ofsaid carrier engageable with said controlling means.

4. The combination with an intermittently rotatable carrier, of anaxially movable, rotatable spring-actuated screw cutting tool, a drivingshaft extending into the rotary centre of said carrier, a cam-facedcoupling member operatively engageable with said shaft and said tool,coupling controlling means on said carrier and engageable with saidcoupling, means on said tool engagea'ble with said coupling, arelatively stationary member outside of said carrier in the rotatablepath of said controlling means, and operating tappets on said carrier.

5. The combination with an intermittently rotatable tool carrier, of anaxially movable rotatable spring-influenced screw cutting tool. housedin said carrier, a driving shaft extending into the rotary centre ofsaid carrier, a cam-faced coupling member cooperating with said shaftand said tool, a displaceable rack bar engageable with said coupling,operating means for said rack bar, means on said tool engageable withsaid rack bar, and relatively stationary operating tappets outside ofsaid carrier in the circular path of movement of said. rack baroperating means.

In testimony whereof I aflix my signature.

THEODOR EUGEN BUSCHMANN.

